 | Education - 1890 - 770 pages
...four hypotheses regarding two straight lines from which they can be proved parallel. 4. Prove that in an isosceles triangle the angles opposite the equal sides are equal. 5. When are polygons mutually equiangular ? Explain the term homologous sides. 6. To what is the sum... | |
 | Edward Albert Bowser - Geometry - 1890 - 420 pages
...triangle is 40° 14' 48", what is the value of the other acute angle ? Proposition 25. Theorem. 111. In an isosceles triangle the angles opposite the equal sides are equal. Hyp. Let ABC be an isosceles A having AC = BC. To prove /_ A = Z B. Proof. Draw the line CD from the... | |
 | Seth Thayer Stewart - Geometry - 1891 - 428 pages
...XIV. 5§1. Theorem Many propositions fire equally true with spherical and plane triangles ; thus, I. In an isosceles triangle, the angles opposite the equal sides are equal. II. If two angles of a triangle are equal, the sides opposite are equal. III. If a triangle is equilateral,... | |
 | Thomas J. Foster - Coal mines and mining - 1891 - 444 pages
...greater side is opposite the greater angle, and the greater angle is opposite the greater side. 7. In an isosceles triangle the angles opposite the equal sides are equal. 8. In any triangle the sum of the three angles is equal to two right angles, or 180°. 9. If two angles... | |
 | George Bruce Halsted - Geometry - 1896 - 208 pages
...axis BD, ^ BDC will fall within 4 ADB, and therefore C must fall between A and B. 224. Corollary I. In an isosceles triangle, the angles opposite the equal sides are equal. 225. Corollary II. If two angles of a triangle are equal, the triangle is isosceles. 226. If we join... | |
 | William Chauvenet - 1893 - 340 pages
...the one are respectively equal to a side and the two adjacent angles of the other. PROPOSITION VIII. In an isosceles triangle the angles opposite the equal sides are equal. Corollary. The straight line bisecting the vertical angle of an isosceles triangle bisects the base,... | |
 | Education - 1893 - 568 pages
...angle of one are equal, respectively, to two sides and the included angle of the other. 13. Theorem: i. In an isosceles triangle, the angles opposite the equal sides are equal. 2. If two angles of a triangle are equal, the opposite sides are equal, and the triangle is isosceles.... | |
 | Seth Thayer Stewart - Geometry - 1893 - 262 pages
...SPHERICAL TRIANGLES. 5§1. Many propositions are equally true~with spherical and plane triangles ; thus, I. In an isosceles triangle, the angles opposite the equal sides are equal. Draw arc of great О from vertex to middle of base. The two Дs have respectively = sides (hyp. and... | |
 | Webster Wells - Geometry - 1894 - 400 pages
...conclusions is contrary to the hypothesis that BC is greater than EF. PROPOSITION XXX. THEOREM. 91. In an isosceles triangle, the angles opposite the equal sides are equal. Let AC and BC be the equal sides of the isosceles triangle ABC. To prove ZA = Z B. Draw CD perpendicular... | |
 | George Albert Wentworth, George Anthony Hill - Geometry - 1894 - 150 pages
...HARVARD COLLEGE, June, 1891. In solving problems use fur w the approximate value 3\. 1. Prove that in an isosceles triangle the angles opposite the equal sides are equal to each other. The area of a certain isosceles triangle is 50 square feet and each of its equal sides... | |
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In an isosceles triangle, the angles opposite the equal sides are equal. 
